To enter my router WEP password requires numbers and CAPS to be entered. It has driven me crackers entering CAPS when the default is lower case. I discovered the following fix:-
Settings -> General -> Keyboard -> Enable Caps Lock
Once this is enabled, tapping the shift key twice will turn on caps lock. When the caps lock is enabled, it will glow blue.
Not so brilliant, the caps lock will not stay locked as you toggle back and forth between alpha and numeric keyboards, bummer!
However - the simple answer is to enter your WAP password into Notes app and then when you need it cut and paste, simple really. It works for all my other network passwords as well, hooray!)